<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .nav{
            border-top: 3px solid blue;
            border-bottom: 1px solid wheat;
            line-height: 30px;
          
        }
       .nav a{
            text-decoration: none;
            display: inline-block;
            height: 30px;
            line-height: 30px;
            font-size: 14px;
            margin-left: 20px;
            background-color: #fff;
            padding: 0px 8px;


        }
        .nav a:hover{
            color: orange;
            background-color: red;
            text-decoration: double;
        }
    </style>
</head>
<body>
    <div class="nav">
        <a href="#">哈哈</a>
        <a href="#">哈哈</a>
        <a href="#">哈哈</a>
        <a href="#">哈哈</a>
    </div>
</body>
</html>